// Define function getUrlVars() to extract all variables.
   function getUrlVars()
   {
   var vars = [], hash;
   var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
   for(var i = 0; i < hashes.length; i++)
   {
   hash = hashes[i].split('=');
   vars.push(hash[0]);
   vars[hash[0]] = hash[1];
   }
   return vars;
   }
// Select variables.
   var variable_url = getUrlVars()